1. Field of the Invention
The present invention relates to a method for calculating the effective volume of a diesel particulate filter. More particularly, the present invention relates to a method for calculating the effective volume of a diesel particulate filter that enables regeneration timing of soot to be precisely determined by precisely calculating the effective volume of the diesel particulate filter based on a learned value of an ash coefficient and reduces time and cost for modifying an ash amount.
2. Description of Related Art
Generally, as ash becomes piled up in a diesel particulate filter, the effective volume where soot can be piled up is decreased. Such an effective volume and a temperature of an exhaust gas are principal factors for determining regeneration timing of soot in a diesel particulate filter.
According to known methods, a change of effective volume caused by ash according to a travel distance of a vehicle and fuel consumption is stored in a map table. Therefore, various efforts have been exerted so as to improve accuracy in prediction of the soot pile by using the map table. However, since a great number of experiments should be carried out in order to make the map table, a great amount of time and cost are needed for making the map table.
Further, since the soot pile is influenced by various factors besides the travel distance of the vehicle and the fuel consumption, there are problems such that the map table is not accurate.
To solve such problems, a method for calculating the change of the effective volume caused by the ash has been invented. According to the method, various driving modes are divided into three representative driving modes, e.g. city mode, highway mode, and mixed road mode, and ash pile and pressure difference caused by the ash according to the fuel consumption and oil consumption is calculated at respective modes. After that, the change of effective volume caused by the ash is calculated. However, since fuel consumption and oil consumption are changed variously according to type and state of the vehicle, the change of the effective volume caused by the ash must be modified.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.